Human skin undergoes changes with age due to a variety of internal and external factors. Specifically, with respect to the internal factors, the secretion of various hormones that regulate metabolism is reduced, the function of immunocytes and the activity of cells decline, and thus the biosynthesis of immune proteins and structural proteins that constitute a living body is reduced. With respect to the external factors, the amount of ultraviolet rays reaching the earth s surface is increasing due to destruction of the ozone layer, and as environmental pollution becomes ever more serious, free radicals and reactive oxygen species increase. As a result, skin thickness decreases, wrinkles increase, skin elasticity decreases, the skin color becomes darker, skin troubles frequently arise, and age spots, freckles and dark spots also increase.
As aging progresses, the content and arrangement of collagen, elastin, hyaluronic acid and glycoprotein that constitute the skin are changed or decrease, and oxidative stress occurs due to free radicals and reactive oxygen species. Also, it is known that, as aging progresses or by the action of UV rays, in most cells of the skin, the biosynthesis of cyclooxygenase-2 (Cox-2) producing proinflammatory cytokines known to cause inflammation increases, the biosynthesis of matrix metalloproteinase (MMP), which degrades skin tissue, increases due to these inflammatory factors, and the production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) increases. That is, due to intrinsic aging that naturally progresses, the activity of cells is reduced, and the biosynthesis of substrates is reduced due to minute inflammation. In addition, due to external factors such as an increase in stress caused by various harmful pollutants and an increase in reactive oxygen species caused by the sunlight, degradation and denaturation are accelerated, and thus the skin matrix is broken and becomes thinner, while various symptoms of skin aging appear. For this reason, many studies on active ingredients that can prevent and ameliorate such aging phenomena are being conducted.
Meanwhile, it is known that reactive oxygen species that are produced by various physical, chemical and environmental factors, including an in vivo enzyme system, reductive metabolism, chemicals, pollutants and a photochemical reaction, cause cell aging and various diseases including cancer by showing a non-selective, non-reversible destructive reaction against cell components such as lipid, protein, sugar and DNA. In addition, a variety of in vivo peroxides, including lipid peroxides, that are produced as a result of lipid peroxidation caused by these reactive species also cause oxidative destruction against cells to cause various functional disorders, thus causing various diseases. Accordingly, antioxidants such as free radical scavengers capable of eliminating such free radicals and peroxide inhibitors can be used as agents for inhibiting or treating aging and various diseases resulting from such oxides.
As a result of recent well-being health trends, demand for fermenting natural materials using a natural fermentation method without using artificial factors has increased, and demand for products manufactured using the fermented natural materials continues to increase. However, due to the risk of decomposition and contamination by E. coli bacteria and anaerobic bacteria that are harmful to the human body, it is difficult to use such natural fermentation methods to manufacture actual products. To solve this problem, a method of carrying out sterilization before fermentation, such as a boiling method, was devised, however effective components can be degraded by heat. For this reason, the need to develop a fermentation method that uses a non-sterilization method exists.